#!/usr/bin/env node

const mysql = require('mysql2/promise'),
      log = console.log;

let con = mysql.createPool({
  host: 'localhost',
  user: 'root',
  password: 'ddd',
  database: 'test'
});



async function getAreas() {
  const sql = 'select * from areas';
  
  let [rows] = await con.execute(sql);
  return rows;
  
}

async function addAreas(areaName) {
  const sql = `insert into areas(area_name) values('${areaName}')`;
      
  let [rows] = await con.execute(sql);
  return rows;
          
}

async function updateAreas(oldName,newName) {
  const sql = `update areas set area_name = '${newName}' where area_name = '${oldName}'`;
          
  let [rows] = await con.execute(sql);
  return rows;

}

async function delAreas(areaName) {
  const sql = `delete from areas where area_name = '${areaName}'`;
          
  let [rows] = await con.execute(sql);
  return rows;
                  

}

(async function() {
  //await addAreas('英国');
  //await updateAreas('英国','大不列颠');
  delAreas('大不列颠');
  log(await getAreas());
})();
